Functional roles of Actinomycetota in agroecosystem resilience under climate and environmental stress

Climate change intensifies abiotic stresses such as drought, salinity, and heat, reshaping soil microbial communities and constraining agroecosystem functioning. Actinomycetota (formerly Actinobacteria ), gram-positive filamentous soil bacteria, represent a functionally important yet underexplored component of soil microbial ecology. These microorganisms contribute to nutrient cycling, soil aggregation, and plant-soil system stability by producing osmoprotectants, exopolysaccharides (EPS), phytohormones, and enzymes such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Recent studies, primarily from 2020 to 2025, highlight their ecological relevance under climate and environmental stress. Members of the genus Streptomyces have been shown to improve the physiological performance of crops under drought conditions, while Nocardiopsis alba modulates rhizosphere ionic balance under salinity stress. Beyond stress buffering, Actinomycetota function as multifunctional contributors to soil processes, including pathogen suppression, organic matter turnover, and rhizosphere stabilization, with growing evidence from field-relevant studies. Despite these advances, major translational and ecological knowledge gaps remain, including limited large-scale field validation, formulation instability, and an incomplete understanding of ecosystem-level modulation of greenhouse gas (GHG) emissions. Future research should prioritize integrative, multi-omics-guided trait characterization, climate-relevant field experimentation, and system-level assessments to fully elucidate the role of Actinomycetota in climate-resilient agroecosystems. Adopting a trait-based ecological perspective, this review positions Actinomycetota as key mediators of plant-soil-microbiome interactions under climate and environmental stress.